In 2000, Giuliani's 16-year marriage to Donna Hanover ended very publicly with allegations of two affairs -- one with a former aide, Christyne Lategano, and a second with drug company executive Judith Nathan, whom he later went on to wed.

"He's going through a tough period," Giuliani, 65, told Us of Woods, 33. I know him and at an early stage in my son's career, he was very kind and nice to him. So I know what a nice man Tiger really is, particularly with children. He was extraordinarily generous to my son and my son played golf with him."

About eight years ago, when Giuliani's son Andrew golfed with Woods (father to Sam, 2, and Charlie, 10 months), "Woods showed him how to play and wrote him notes afterwards," the former NYC mayor told Us.

Added Giuliani, "He has a big heart for children. He's a very, very fine man. And people should know the way he treats children." Giuliani told Us his heart goes out the entire Woods family. "We know he's going to get through it," Giuliani told Us.